Vocal Effects: Play with Reverb, Compression and More!

Pop music would be unthinkable without vocals coating in at least some effects. In fact, pretty much any recorded music – vocals included – will come packed with effects these days. If you’re a vocalist and want your voice to sound more up-to-date and want to be able to really slice through the sound of the rest of the band, then vocal effects are a must. In this blog, we take a look at the mass of options available to the modern vocalist – from the common compressor, equaliser and reverb to special effects like tremolos, distortions and harmonizers. Try something new and give your live and recorded vocals some proper impact.

This blog was written by Alfons Verreijt, the developer of the VocalFeedback method and author of the book The Essentials of the Voice.

Unnatural?

“Almost any musician will be continuously obsessed with their sound and the gear involved”, says vocal coach, Alfons Verreijt. “So it always surprises me when singers are only focussed on the sound of their voice. Your voice is just one part of a whole that ultimately makes up the vocal sound. That ‘whole’ is a long signal path or chain that starts with the voice, which then gets sent through a microphone, a cable, and on through effects and an amplifier before coming out of the speakers at the other end. Every step has an impact on the vocal sound that results. As a vocalist, if you want to have a say in how you sound, you need to go further than just working on your voice and choosing the right microphone.”

But, do effects make vocals sound unnatural? “To a certain extent – yes,” admits Alfons, “But to be honest, pop music isn’t meant to sound natural. All recorded pop music is rammed with effects – the vocals included. To sound contemporary, any vocalist just needs to go along with it – even if it’s only because it’s what your audience expects. Effects can also really help make the vocals stand out over the rest of the instruments. The alternative is do something dramatically different and make something completely unique using minimum effects. But to do that, you need to actually know a thing or two about effects so you can pick the right ones.”

In this blog, we start by looking at your foundation effects like equalisers, compressors, reverb and delay. In the second part, we’ll cover more ‘special’ effects. All of these effects are available as both physical hardware and software and, when it comes to software effects, you probably already have a library of them in your recording software, so you can add them to your work as plugins (for more info about plugins, see our series about recording at home).

Valve Preamps

The signal sent from a microphone is always really weak – which means the sound is really quiet. So, before it can continue through the signal path, it needs to be jacked up a little bit. You can do this easily using a microphone preamp. When working in a recording studio, you’ll almost always use a valve preamp, which is actually fairly old tech. The valve, or tube inside the preamp, adds some harmonic distortion but in such a way that it actually makes things sound natural and pleasant. In our digital age, it’s quite nice that big studios still add an analogue step to the chain just after the microphone, and this has a welcome effect, since it stops everything from sounding too clean and clinical. Valve preamps are used in professional studios and home studios, but they’re very rarely used for live shows.

The Compressor/Limiter

One of the most essential effects when it comes to the vocals is the compressor/limiter. Officially, a compressor does something different to a limiter, but they’re usually mentioned in the same breath. Compression means ‘squeezing’, which is literally what this effect does to sound, so a compressor unit or plugin helps to flatten the dynamics by reducing the difference between louder parts and quieter parts. It works like a kind of automatic volume control that steps in to push down the volume as soon as the input signal level raises above a certain threshold value. You can set the threshold value yourself and you can set other details like, how fast the compressor responds. This way, volume peaks in the sound are pushed back down and the volume of quieter parts comes closer to the volume of louder parts. In fact, at more extreme settings, the difference between loud and quiet can almost be eliminated. From there, the overall volume can be turned up without fear of any unwanted, distorting volume peaks.

Originally, compression was intended to simplify the mixing process, but it’s also often used to make an element sound fuller, more powerful and more clear within a mix. TV adverts use masses of compression to make sure that the message comes through loud and clear – to the point where it sometimes gets intrusive. The music industry trend of the past few years has been to apply more and more compression to make the music sound louder. Sometimes, you can almost hear the compression ‘pumping’. However, a preference for minimal compression is also on the rise.

Back to the vocals: a little compression can immediately make vocals sound more clear and powerful. In reality, you can only use compression in the recording studio because, if you use it on stage for live shows, you’ll quickly run into some horrible feedback problems.

The Equalizer

Some further colour can be brought out of the sound using an equalizer. When it comes to treating vocals, an equalizer is an unmissable step in the signal chain. An equalizer is used to weaken or strengthen specific frequency bands within the audio spectrums and can be used live as well as in the studio. Every channel strip (the row of control knobs and buttons) of the mixer that you plug the microphone into will include controls for equalizing that channel. Most of the time, a channel strip will have three or four of these controls. If there’s a set of three, you gain control over the bass, the mid and the treble frequencies. If there’s a set of four, then you might get control over the bass, the low-mid, high-mid and treble frequencies, or you get three knobs for controlling the bass, mid and high frequencies and an extra knob for controlling the parametric mid frequencies. With this knob, you can set the frequency range that the mid frequency knob controls.

Space in the Mix

Why bother equalizing the vocals? To make sure the vocals are beautifully coloured in? To a certain extent, yes. But it also has another essential function: it helps create space in the mix for the vocals. By tweaking the frequencies, the vocals suddenly come to the front of the mix, so they sit on top of the drums, the bass, the guitars and keyboards and so on. By taking each individual instrument in the mix and emphasising a specific frequency, you kind of give each part its own space within the audio spectrum. This really benefits the song by making sure that everything is sort of highlighted and has its own place in the mix. The most important frequency range when it comes to vocals lies between the 4,000Hz and 5,000Hz mark (4kHz and 5kHz). By strengthening this frequency band, you’ll gain clear and intelligible vocals, because human hearing is naturally tuned to it. Also, it can be a good idea to weaken the lower frequencies of male voices a touch, otherwise it might get in the way of the lower frequencies of the bass and guitars. Weirdly, this won’t make the vocal sound weak and thin because the human brain has a knack of naturally filling in the gaps, so will literally add the frequencies it expects to hear.

“Before you start fiddling with the equalizer knobs, you need to have a clear image of how you want things to sound,” Alfons advises. “So it’s worth experimenting at home first. This will give you a good foundation that you can start building on for rehearsals, shows and recording sessions.” However, it’s worth noting that you can’t just dial up unlimited frequency ranges, because on stage, it’s only going to lead to feedback. If you are getting feedback, then try to isolate the problem frequencies and dial them back a bit. With a parametric equalizer, you can actually shift the amplified frequency range to pinpoint where the problem lies, so you can turn that specific frequency range down and get rid of the feedback. Usually, this does make things sound a little bit more dull, but that’s a compromise you sometimes have to make.

Reverb

From equalizing, we move onto reverb, delay and echo. By applying reverb to vocals, you can make it sound like you’re singing in an entirely different space, where your voice literally reverberates off virtual walls. Reverb is like the special sauce for vocals, but it can be a pretty strong sauce so tread carefully. Too much reverb can easily make your vocals sound like you’re singing in a cheap karaoke bar.

There are various different kinds of reverbs like, room, stage, hall, church and so on. Often the music genre you’re working on will dictate the kind of reverb that will work best. In a straight-up rock band, it won’t necessarily work if the singer sounds like they’re standing in a gigantic cathedral. Adding a little reverb to the vocals and other instruments can smooth out the overall sound – as long as you use reverb in small doses. Too much reverb can be counterproductive – especially for the vocals. With vocals, it can be better to aim for as dry a sound as possible. So definitely use some reverb, but no more than is strictly necessary, especially if the vocals are surrounded by instruments – and they usually are. Less reverb will make sure that you can make out the lyrics and, almost more importantly, less reverb makes sure that the vocals sit more up-front in the mix so, to the listener, they actually sound louder. With masses of reverb, the vocals are almost pushed into the background. It can make them sound quieter and far off in the distance, which makes the audio image confusing because in a pop song, the vocals need to be sitting on top. Here, you can see a similar thing happen as with equalizing. Reverb and equalizing actually go hand in hand because they can work together to ensure that the vocals are sitting right up front.

Echo & Delay

Echo and delay effects are closely related to reverb. The echo produced by audio tech works in exactly the same way as the echo as you’d experience in real life – so sound bouncing back at you off the walls of a cave (for example) and sounding like it’s being repeated. Echo is used less than reverb and delay. Delay is a bit like echo since the sound is recorded, delayed and then repeated a little after the original sound was made. With a short delay things sound a bit like they’re doubled, but the repeat is very slightly delayed. The first delay effect units were actually tape recorders and formed a big part of styles like rockabilly. Vocal coach, Alfons likes to use a little delay, but prefers to keep the delay time really short – just a couple of milliseconds: “That way you get this sort of doubling effect that gives the voice more body. I use it almost all the time.” As well as in the recording studio, you can use delay on stage.

Always Hit the Low-Cut

Almost any mixing desk will feature a low-cut button, especially if you’re looking at a channel with a microphone input. As soon as you press the low-cut button, the lowest portion of the sound, so the lowest frequencies (usually anything lying under 100Hz) is filtered out. This gets rid of any unwelcome sounds picked up by the vocal microphone, like a tapping foot or a kick drum. It’s actually always a good idea to turn on the low-cut filter on a microphone channel. You won’t be missing any of the vocals since they never dive below the 100Hz mark anyway.

Singing in a Guitar Band

If you’re singing in a band with two or more guitars, then it can be harder to make sure that your voice is cutting through the mix. In that case, you could ask the guitarists to roll back the high-mids and then turn up the high-mids of the microphone channel. The guitarists shouldn’t have any problem with this since it won’t make them sound any less heavy. A lot of guitarists don’t realise that their full and often loud sound can cover up and drown everything else out. If you’re singing in a band with just acoustic guitars, then there’s usually no need to equalize them.

Special Effects

The effects we’re about to look at now are almost all guitar effects. In other words, most of the time they’re used by electric guitarists, or that’s what they were originally developed for. You can use guitar effects for other instruments, like keyboards and synthesizers, but also for vocals. However, these more special effects are used much less than your foundation effects like equalization and reverb, but because they’re special, these kinds of effects can be used to give a song a really unique feel. We’ll start with the modulation effects: tremolo, chorus, phaser, flanger, wah-wah and Leslie (or rotary). All these effects operate in a similar way so can be considered a sort of family of effects, all of which play around with a waveform, the shape of which can be warped by tweaking the speed and often the depth.

Tremolo

We’ll start with tremolo. The tremolo arm, or whammy bar of an electric guitar is used to vary the string tension to create a vibrato effect, which actually means that ‘tremolo’ isn’t the right term here – it’s just a name that’s stuck over the decades since the first ever electric guitars. In reality, a tremolo effect is not the same as a vibrato effect, because it plays with the volume of a sound by quickly ‘fading’ it on and off. Some guitar amplifiers like the Fender Twin Reverb come with a built-in tremolo – but weirdly, it’s actually called a vibrato. When tremolo is applied to a sound, like vocals, the volume of the sound is repeatedly dipped, as if the sound is turned into waves. The speed of these waves can be adjusted as well as the depth (so how far the volume of the sound is pushed down between each wave). You can actually perform a tremolo effect with nothing but your voice, but there are also effect units you can use and, while you won’t necessarily use it throughout a pop song, adding a little tremolo here and there to emphasise certain parts can lend a really unique touch.

Chorus

Chorus is another guitarist’s favourite. This effect makes a sound feel broader and richer. What chorus does it take an original sound, split it in two and then play back both sounds at close-to the same pitch. The natural chorus sound of a real choir or double-stringed instrument like a mandolin is produced because, while multiple voices are singing the same note, the very slight pitch differences and the differences between those voices is what widens the sound and makes it feel far more rich. In short, movement is added and this sort of effect can also be achieved with electronic chorus effect units. As well as splitting the sound in two and playing the resulting sounds back at a slightly different pitch, a chorus effect also adds a touch of vibrato and the depth and speed of the vibrato can be adjusted. When you turn the depth and speed controls all the way up, you get a really weird sound, but set at just the right level, you can make something suddenly sound bigger. You can also use a stereo chorus, where the two channels remain split or just use a standard mono chorus that outputs a mix of the two channels. The only downside of singing through a chorus effect is that, sometimes, it can make it harder to sing in tune.

Phaser & Flanger

The phaser is a bit like a chorus, since it also takes the original sound and splits it into two channels. One of the signals is then moved out of phase with the original signal to create peaks in the frequency spectrum. These peaks have an irregular shape and are constantly shifting, which creates a sort of sweeping effect in the sound.

A special version of a phaser is a flanger. A flanger also makes a copy signal and puts it out of phase with the original signal, but the peaks in the frequency spectrum are manipulated in such a way by a flanger that they have a kind of regularity to them. A kind of bump is created in the frequency spectrum that constantly shifts. In other words, a specific part of the frequency spectrum is emphasised and that part keeps moving. It has a similar effect to constantly turning the knobs of an equalizer up and down. It’s this moving frequency peak that makes it feel like the sound is kind of ‘walking’. A well-known example of how you can use a flanger can be heard during the break of Listen to the Music by the Doobie Brothers.

Wah-Wah, Leslie & Distortion

Another effect that plays with frequency spectrum ‘bumps’ is the wah-wah pedal. A wah-wah pedal is like the accelerator pedal of a car, and when you push it down, a specific part of the frequency spectrum (which you set with your foot) is emphasised. This literally makes an instrument sound like it’s saying ‘wah-wah’ – hence the name. This is another classic guitar effect, but why not use it for vocals? It’s definitely worth experimenting with and seeing what you can come up with.

Now we come to the Leslie effect, which originates from the Leslie rotary speaker that was used to amplify Hammond organs in the sixties and seventies. Inside the cabinet, the speakers literally rotates, which is why this effect is also often referred to as a rotary effect. This kind of effect is also used a lot by harmonica players and guitarists because it produces a kind of natural vibrato by recreating the Doppler effect. This is the effect that happens when sound travelling towards a listener gradually rises in pitch before it gradually lowers in pitch as it travels away from you – like the effect of a passing police car with the siren blaring. The construction of the original Leslie speaker also adds a specious effect, because the sound is bounced around inside the box and off the walls.

One of the most classic guitar effects is distortion, which was originally created by literally overdiving the valves or transistors of guitar amplifiers. These days, you can also apply distortion with an effect pedal or software plugin. Distortion can come in a few slightly different forms: classic distortion, overdrive (which is a little lighter) and fuzz (which is a little more extreme).

The Harmonizer

Now we come to the more common vocal effects, starting with the harmonizer. With this effect, you add a second, third or even more voices to your own voice, all in a specific harmony. Here’s how it works: the harmonizer is connected to a keyboard (this could also be a guitar) and, depending on the chords being played, produces a second and third voice, based on your own voice. This creates a sort of backing choir but that choir is a little bit limited, because it can only sing what you sing but in a harmonised pitch. This means that your choir has exactly the same timbre and timing as your own voice, so in reality, could never truly replace a real choir. However, what really works with a harmonizer is scatting, where your jazz vocal licks are layered with harmonies. Just think what a small brass section put through a harmonizer could sound like!

The Vocoder & Talkbox

The original Talkbox is a unique instrument in its own right. On the face of it, it’s just an effect pedal, but this pedal has a long hose attached to it. Why? The idea is to plug an instrument like an electric guitar into the Talkbox and mount the end of the hose next to your microphone. When you play your guitar, the sound is sent through the hose and, by placing your mouth over the end of the hose, you create a little resonance chamber. By changing the shape of your mouth – especially when forming vowel sounds – the sound of the guitar is shifted, making it sound like your guitar is literally ‘talking’.

The vocoder does a similar thing – but without the hose. Here, you’re plugging a microphone into some form of synthesizer so that, when you sing or talk into the microphone, it’s turned into the sound of the synth.

Autotune & Melodyne

Now we come to the more contentious vocal effects: Autotune and Melodyne. Autotune appeared towards the end of the nineties and was originally intended as a tool for ensuring that a vocal is in perfect tune. It does this by adjusting the note being sung so that it matches the nearest pure note. Because this happens in real-time (so it’s not something that’s used to edit a recording later) you can also use Autotune live. You can adjust the speed of Autotune (the time it takes to re-tune a note) and when the speed is at a slow setting, you get a sort of whining effect that can actually be seen as an effect in itself. A while after Autotune was introduced, a software version was developed that can be used as a plugin in the DAW recording software of a computer.

Then, in the 2010s, Melodyne came along. This exclusively software-based effect was a sort of more advanced take on Autotune and, just like Autotune, Melodyne is able to tune the pitch of a slightly sharp or flat note to the nearest pure note. With Melodyne you can do this in real-time or manually, after recording. But what really makes Melodyne different is that you can apply rhythmic corrections and even mess around with and completely change the melody. Famously, when you get too heavy-handed with Melodyne, the vocals can quickly sound a bit synthetic, because it simply starts sounding too good – too tight. You can hear many glaring examples of Melodyne overkill in the American TV series Glee, where Melodyne was used on almost every song.

“Singing in absolutely perfect tune is actually impossible,” insists vocal coach Alfons. “If you do manage it, then you’ll only end up sounding unnatural. Almost anyone sings just under the note, or at least starts singing a note just a touch lower. As long as you view it as ‘good enough’ then it actually is good enough. And, if the note isn’t quite on pitch but ends with vibrato, you’ll hit the right pitch eventually and, to the listener, this actually feels like a relief. It feels satisfying.”

Find out more about pitch-correction tech in this dedicated blog.

Experimentation

When it comes to using effects, Alfons offers the following advice: “No matter the effects you’re using, the foundation of your voice needs to be solid. From there, you can start thinking about what kind of effects you can add to give a song its own specific signature. If you want to experiment with an effect, then you can get a cheap pedal or plugin and sing into your computer. Download a program like Reaper from reaper.fm, which you can use for free for 60 days. You can get it for Apple, Windows and Linux and it not only puts a complete recording studio on your computer, but comes with over 40 effects included. All you need to do is plug a microphone into your computer and start playing.” Of course, you can also go for any other DAW recording software.

Experiment with Multi-Effects

A multi-effect unit literally houses multiple effects that can be coupled and combined in a number of ways. You don’t necessarily have to go for a vocal effect unit either. Does the guitarist from your band already have a multi-effect pedal? Ask them if you can borrow it for a bit and experiment with it. You never know what you might find out!

The Loop Station

Loop stations aren’t really effects, but can be a really interesting addition to your effects arsenal. These boxes are loved by vocalists and musicians alike since they allow you to record and loop phrases, overdub and sing along to your own self-made loops. The loop station has even helped some musicians to launch their entire career and on YouTube, you’ll be able to find more than enough good examples of how you use a looper. Loop stations made by Boss (Roland) are the most well-known, like the RC-500. With a loop station, you can record vocals, you can beat box, and you can record an instrument – all with one unit, meaning you can create entire songs, on your own and from scratch. Models like the RC-500 also feature multiple tracks, so you can record a beat on one track, a guitar on another track and backing vocals on another track. You can also add overdubs to each track, stop each looping track separately to create dynamics and boost, say, the chorus. A loop station can offer so much potential when it comes to writing and performing and it’s a great tool for experimenting and practising at home.